Typically, a solid oxide fuel cell (SOFC) employs a solid electrolyte of ion-conductive oxide such as stabilized zirconia. The solid electrolyte is interposed between an anode and a cathode to form an electrolyte electrode assembly. The electrolyte electrode assembly is interposed between separators (bipolar plates). In use, normally, predetermined numbers of the electrolyte electrode assemblies and the separators are stacked together to form a fuel cell stack.
As the fuel gas supplied to the fuel cell, normally, a hydrogen gas produced from hydrocarbon raw material by a reformer is used. In general, in the reformer, a reformed raw material gas is obtained from hydrocarbon raw material of a fossil fuel or the like, such as methane or LNG, and the reformed raw material gas undergoes steam reforming, partial oxidation reforming, or autothermal reforming to produce a reformed gas (fuel gas).
In this regard, a fuel cell system having a single unit case containing a fuel cell, a reformer, a power converter for converting direct power electrical energy generated in the fuel cell according to a power supply output specification, a control device, and auxiliary devices is known.
For example, in a fuel cell power supply apparatus disclosed in Japanese Laid-Open Patent Publication No. 2003-297409, as shown in FIG. 10, lateral bars 1001a, 1001b are provided in a frame 1001 of the unit case to vertically divide the space in the frame 1001 into three stages. A reformer 1002 is provided on the lateral bar 1001a in the upper stage, and a control device 1003 and a fuel cell 1004 are provided on the lateral bar 1001b in the middle stage such that back sides of the control device 1003 and the fuel cell 1004 face each other. Heat insulating material 1003a is provided on the back surface of the control device 1003, and heat insulating material 1003b is provided around the control device 1003 to protect the control device 1003 from the ambient hot environment.
Auxiliary devices such as a fuel pump 1005 for supplying a raw fuel to a reformer 1002 and an air pump 1006a for supplying an air as a reactant gas to the fuel cell 1004 are provided on the bottom plate of the frame 1001. An air pump 1006b for a reformer burner is provided on an auxiliary rack 1001c at an upper position of the frame 1001, and a PG burner 1007 is provided in front of the air pump 1006b for the reformer burner. A power converter 1008 is provided on a side of the fuel cell 1004 on the floor of the frame 1001.
Further, for example, in a fuel cell generator apparatus disclosed in Japanese Laid-Open Patent Publication No. 2006-086017, as shown in FIG. 11, a case 1011 contains a fuel cell 1012, a fuel reformer for producing a fuel gas to be supplied to the fuel cell 1012, a gas supply apparatus 1013 for supplying a gas to be reformed to the fuel reformer, a water supply apparatus 1014 for supplying water to the fuel reformer, and a power converter 1015 for converting direct current electrical energy generated in the fuel cell 1012 into alternating current electrical energy, and supplying the alternating electrical energy to external loads.
The fuel cell 1012 and the fuel reformer are provided at an upper portion in the case 1011, and the power converter 1015, the water supply apparatus 1014, and the gas supply apparatus 1013 are arranged at a lower portion in the case 1011 such that the gas supply apparatus 1013 is positioned between the power converter 1015 and the water supply apparatus 1014.
Further, for example, in a fuel cell apparatus disclosed in Japanese Laid-Open Patent Publication No. 2006-140164, as shown in FIG. 12, a package 1021 is provided, and a purifier 1022, an ion exchanger 1023, and a desulfurizer 1024 are provided adjacent to a front panel 1025 serving as an outer panel of the package 1021. The purifier 1022, the ion exchanger 1023, and the desulfurizer 1024 are components that require maintenance.
Thus, the components that require maintenance are not provided inside the package 1021, but provided adjacent to the front panel 1025 serving as the outer profile of the apparatus body. According to the disclosure, in the structure, maintenance of the components that requires replacement, regeneration or the like for continuing operation of the fuel cell apparatus can be carried out easily.